File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

ACCDB file extension

Access 2007 Database File

Database Files

AZW file extension

Amazon Kindle eBook File

eBook Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

FLA file extension

Adobe Flash Animation

Developer Files

LNK file extension

Windows File Shortcut

System Files

MDB file extension

Microsoft Access Database

Database Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

SITX file extension

StuffIt X Archive

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

WMV file extension

Windows Media Video File

Video Files

WSF file extension

Windows Script File

Executable Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

YUV file extension

YUV Encoded Image File

Raster Image Files

3DS file extension

3D Studio Scene

3D Image Files